Mycobacterim tuberculosis infects approximately2 billion people, of whom greater than 2 million will die each year of tuberculosis.With the emergence of multidrug resistant strains and the growingHIV epidemic, the global problemof tuberculosisis worsening.In the last several years the role of the innate arm of the immune response in the control of M. tuberculosis infection has become apparent. Although this response is often adequatefor long term containmentof the bacilli in healthy individuals, it is insufficient for clearance of the infection. Our recent efforts, indicatethat M. tuberculosis possesses specific mechanismsfor the subversionof immune effector populations.Through understanding these immune evasionmechanisms we will be able to design and develop more effective tuberculosisvaccines. To do so, we will utilizecutting edge high-throughput technology to develop a full array M. tuberculosis deletion library. This invaluable tool will enable the elucidationof the molecular basis for this immune evasion, part of which we have found is mediated by a large gene cluster conserved within pathogenic Mycobacterial species.